Islamabad military blames terror 'sanctuaries in Afghanistan' for the Sehwan suicide bomb blast.

Pakistan has shut the border crossing with Afghanistan for an indefinite period after a powerful bomb ripped through a Sufi shrine, killing more than 70 people. Islamabad officials say all forms of communications have been stopped at the frontier over security concerns.

The military's spokesperson Major General Asif Ghafoor also wrote on Twitter confirming that the border is being closed.

Ghafoor went on to add: "Recent terrorist acts are being executed on directions from hostile powers and from sanctuaries in Afghanistan. We shall defend and respond." The border was opened only in August 2016 and remained one of the key points for both vehicular and pedestrian movement. The region has also witnessed several clashes in the past.

Recent Ts acts are being exec on directions from hostile powers and from sanctuaries in Afghanistan. We shall defend and respond.

Emergency operations are still on in Sehwan with army personnel ferrying dead bodies and wounded from the blast site to hospitals. No less than 250 people are thought to have been injured in the attack. Several are reported to be in critical condition.

"Almost all the bodies were brought here. We have handed over 26 bodies to the heirs of the deceased, while those that remain unidentified are at the hospital," Moinuddin Siddiqui, medical superintendent of the Sehwan Taluka Hospital was quoted as saying.

Pakistan has been reeling under a spate of Islamist onslaughts over the last few days. Previous attacks targeted areas in Lahore, Quetta and Mohmand Agency, with the latest one in Sehwan being claimed by the dreaded Islamic State (Isis).